Temperature control device



June 13, 1939. I

I I TEMPERATURE CONTROL DEVICE Filed Oct. 50, 1957 Inventor TheodotfleA. Rich b $4 447 W Y Hi8 AUG or'ney.

Patented June 13, 1939 2,162,589

UNITED STATES PATENT OFFICE TEMPERATURE CONTROL DEVICE Theodore A. Rich,Schenectady, N. Y., assignor to General Electric Company, a corporationof New York Application October 30, 1937, Serial No. 171,927

3 Claims. (01. 236-7) This invention relates to temperature controlmachine having an ironing roll i and an irondevices, more particularlyto temperature control ing buck I i. The ironing roll and buck aresupdevices for ironing appliances, such as a rotary ported on a framel2. It will be understood that or flat-plate ironer, and it has for itsobject imthe ironing buck will be pivotally mounted, as on 5 provedtemperature control means for ironing an arm 1211, so that it can beswung away from 6 devices of this character. and toward the roll. Itwill also be understood In ironing machines, such as rotary and flatthatsuitable mechanism will be provided for plate ironers there is provideda buck carrying an driving the roll. ironing shoe between the. ironingface of which The ironing buck II is provided with an iron- 10 and asuitable roll or plate, the fabrics are passed ing shoe i3 having anironing face or surface 10 to be ironed. oftentimes these machines arethat faces the ironing roll l0 and between which provided with athermostat for controlling the face and the roll the fabric is directedto be temperature of the ironing shoe. This thermoironed, the fabricbeing caused to pass through stat is usually carried by the buck on theside of the machine by the rotation of the roll l0.

the ironing shoe opposite the ironing face. The The ironing shoe I3 isheated by an electrical 5 thermostat is located to respondto thetemperaheating element l5, preferably of the sheathed ture of the shoeso as to hold this temperature type, such as described and claimed inthe United as nearly constant as possible. Inasmuch as it States patentto Charles C. Abbott, No. 1,367,341, is separated from the ironing faceby at least the dated February 1, 1921. Briefly, this element thicknessof the shoe, it does not under certain comprises va helical resistanceconductor I6 20 conditions of operation follow the temperature ofmounted in a metallic sheath I1 and supported in the'ironing face withsufficient rapidity to hold an spaced relation with reference to thesheath and even temperature. Thisis particularly true when electricallyinsulated from it by a compacted a. cold wet piece of fabric is broughtinto contact mass of electrically insuatingv material l8, such 1 withthe ironing face. When this happens, heat as magnesium oxide. As shown,the heating eleis rapidly drawn from the ironing face and the ment ismounted in channels l9, and is secured moisture in the fabric isconverted into steam. the channels by means of barriers 20 positionedThis causes a rapid drop in temperature in the over the mouth of thechannels. The heating ironing face from the desired ironing temperature.means i5 is provided with terminals 2| positioned This sudden drop isnot experienced by the theradjacent each other, as clearly shown inFig. 1. o

mostat which is remotely positioned'with refer- Mounted onthe buck ii onthe .side of the ence to the face. Only after the lapse of some ironingshoe l3 opposite its ironing face is a time is the thermostat cooled soas to operate to temperature control device 22 for controlling the applyheat to the plate to reestablish its ironing energization of the heatingmeans l5. As shown,

temperature. This results in poor regulation. the temperature controldevice is supported on In accordance with this invention, I provide inthe outer casing 23 of the buck, and preferably the ironing shoe a duct,or series of ducts, oppowill be mounted in a recess 24 provided in thesite the thermostat and leading from the ironing layer of insulation 25that usually is provided in face so that when steam is generated by thethe ironing buck to prevent heat from traveling pressing operation, itvflows through the duct or through its outer casing. The thermostatic de-40 ducts to and around the thermostat. The thervice, as shown, comprisesa bimetallic thermo mostat is h y p y Cooled as t oni static bar 25which is formed of two metals havface itself is rapidly cooled. Thisresults in a 'ing dissimilar temperature coeflicients of expanvery eventemperature regulation. sion, such as invar and steel, rigidly securedto- For a more p e understanding of his ngether from end to end in anysuitable manner, 45

vention, reference should be had to the accomas by welding. pany n d awi which Fi 1 is a ra ent ry .One end of the bimetallic thermostat bar 26is elevation o an on machine embodying his fixed and is connected to oneof the terminals v i p r being k n w y so as to il- 2| of the heatingmeans l5. Its other end is free lus -rate certain details ofconstruction; and Fig. to move and carries a switch contact which 00- 502 is an enlarged fragmentary sectional view operates with a fixed switchcontact 21 that is taken through the line 22 of Fig. 1 and lookingconnected with the opposite terminal 2i of the in the direction of thearrows. heating means. The thermostat 22, it will be ob- Referring tothe drawing, this invention has served, is located in the buck torespond to the been shown in one iormas applied to an ironingtemperature of the buck, and it controls the temperature in the ironingshoe in accordance with this temperature. The setting of the thermostatcan be varied by means of an adjusting screw 28 which bears on thethermostatic bar to vary the tension in the bar, and which, as shown, isaccessible on the exterior of the buck for convenience of adjustment,

The ironing shoe is provided with a duct 29 directed through it andpositioned opposite the thermostatic member 26, as clearly shown in thedrawing. One duct may be used, or a plurality of ducts, as desired. Theduct 26 functions to connect the ironing face of the shoe i3 with thebimetal element 26.

In the operation of the ironing apparatus, it will be understood thatwhen the heating element is energized, the thermostatic bar 26 willoperate to open the energizing circuit of the heating means l5 when thetemperature of the thermostat attains a predetermined maximum, such as450 F., and will close the switch to reapply the heat when thistemperature falls to a predetermined minimum, such as 430 F. It willalso be understood that the fabric M will be caused to travel betweenthe roll I0 and the shoe l3 by the rotation of the roll. The roll mayeither be operated continuously or it may be operated intermittently tosuccessively bring the portions of the fabric into proper ironingposition of the buck. The fabric usually is moistened or dampened beforeit is passed through the machine and when the moistened or wet sectionof the fabric is brought into ironing position and the ironing shoecontacts it, the hot ironing shoe immediately generates steam of themoisture in the fabric and a portion of this steam is forced orprojected through the duct or ducts 29 and into direct contact with thethermal element 26. Thus, when the temperature of the heated ironingshoe l3 rapidly decreases because of its contact with the wet fabric [4and the absorption of heat from the shoe to generate the steam, thethermostat 26 whichhas approximately the initial temperature of the shoeat the instant it contacts the wet cloth will also be cooled quickly bythe impact of the steam on it so that its tmperature will fallsubstantially at the same rate as that of the shoe. In other words, thethermostat will be caused to respondi rnmediately to the drop intemperature of the shoe to control the heating element to maintain thedesired temperature. In this manner, the thermostat will respond tovariations in shoe temperature, whether they be slow or sudden, so as tohold a substantially constant temperature in the shoe with goodregulation.

It will be observed that the bimetallic thermostatic blade is connectedin series in the energizing circuit and that the electric current flowsthrough it. The blade is sufficiently large to afford very littleresistance to the passage of this current, and therefore the heatgenerated by the passage of the current through the blade affects theoperation but slightly. However, even if the thermostatic blade diddevelop an appreciable degree of local heat due to the flow of currentthrough it, this condition would not affect the principle of myinvention. In other words, my invention is applicable equally as well tothe latter case as to the former where little local heat is developed.

While I have shown a particular embodiment of my invention, it will beunderstood, of course, that I do not wish to be limited thereto sincemany modifications may be made, and I, therefore, contemplate by theappended claims to cover any such modifications as fall within the truespirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent of the UnitedStates is:

1. An ironing device comprising a pressing body having an ironing face,heating means for said pressing body, a temperature responsive elementcarried by said pressing body at a point remote from said ironing facecontrolling said heating means responsively to temperature changes insaid pressing body, and said pressing body having a duct between saidpressing body and said tem perature responsive element for conductingsteam generated under said face in the pressing operation into contactwith said temperature responsive element when said ironing face isapplied to moistened articles so as to cool said temperature responsiveelement as the pressing body cools when brought into contact with saidarticles.

2. In an ironing machine provided with a pressing shoe having on oneside an ironing face, and a heating element for said shoe, temperaturecontrol means comprising a bimetallic thermostatic member located on theside of said shoe opposite said ironing face controlling said heatingelement responsively to the temperature in said shoe, and said shoebeing provided with a duct between said ironing face and said thermostat to conduct steam generated under said face to said bimetallicmember to cool it when the temperature of said ironing face is rapidlyreduced by coming into contact with wet fabrics.

3. An ironing machine comprising an ironing roll, a buck having anironing shoe cooperating with said roll to press a fabric travellingthrough the machine between the roll and ironing face of said shoe, anelectrical heating element carried by said buck for applying heat tosaid shoe, a thermostatic element carried by said buck back of saidironing face of said shoe controlling said heating element responsivelyto temperature variations in said shoe, and said shoe having a ductarranged to deliver from said ironing face to said thermostat steam thatis generated by the application of said shoe to wet fabrics so as tocool said thermostatat substantially the same rate that said shoe iscooled when applied to said fabrics.

THEODORE A. RICH.

